“I got into riding because I loved it not because I thought it would be a great way of earning a living,” he said. “After all this, I don’t know if my heart is still in it. There has been so much negativity and I’m still a young man with plenty to offer, especially after this experience.

“In the meantime, I’m looking at a few options: maybe working in the travel industry as a cycle tour guide, or possibly doing some coaching.

“The only constraints I face are on competing in UCI events – it’s a bummer but that’s the state of play. One good thing that has come out of it, though, is that you find out who your real friends are. Fortunately, I’ve got a few who are willing to help me.”

Tiernan-Locke, 29, could still appeal against his guilty verdict at the Court of Arbitration for Sport but he admitted he would probably lose and could not afford the “£80,000-£100,000” he claimed it would cost him if he did.

Questioning the weight of evidence against him, he said: “As before, I don’t feel I’ve been proven guilty. It’s just in the balance of doubt, and it’s not been offered to me.

“There’s no way I can afford to finance another appeal. It would be the equivalent of me buying a small flat in Plymouth. I know riders who have done that but have been left with debts of £80,000-£100,000.

"It’s a big risk and I’m not saying that I wouldn’t appeal again in a second, but with my cool head on, I know it would probably end up in disappointment – again.”

Team Sky, founded on the basis that it would adopt a zero-tolerance approach to drugs, sacked Tiernan-Locke last month the moment he was found guilty by UKAD.

The sample which led to his ban was taken during the Road World Championships in September 2012, three months before he joined Sir Dave Brailsford’s team and days after his Tour of Britain victory – of which he has now been stripped.

However, he did train with Team Sky that year, with his guilty verdict raising questions about their own screening processes, which Brailsford insisted had been tightened since Tiernan-Locke was exposed.

Confirming that the team had appointed a compliance officer, he said last month: “What we have done since is very much look at our governance. We scrutinise in real detail now all the information we’ve got and our monitoring is second to none.”

The use of biological passport data to determine doping violations only came into force in 2008 and Tiernan-Locke’s case was the first handled by UKAD.

Its complexity was exposed by the fact that it is now almost two years since he first provided an anomalous reading and nearly a year since it first emerged that he was under investigation.

However, UKAD’s legal director, Graham Arthur, this week praised the effectiveness of the passport programme, saying: “The athlete biological passport is a vital tool in the prevention and detection of doping and greatly enhances the integrated approach to anti-doping under which we all operate,” he said.

Brian Cookson, the UCI president, added: “I would like to thank UK Anti-Doping for their work in handling this case and providing the rider with a fair and independent hearing.”

That UKAD panel did not dispute that Tiernan-Locke had drunk heavily but expressed “considerable reservations” over his claim that he was still suffering from severe dehydration when he provided his sample two days later, on the eve of a World Championship race in which he finished 19th – the best of any British entrant.